Heat exchanger



Jan. 30, 1934. w, CARRAWAY AL 1,945,394

' HEAT EXCHANGER Filed July 30, 1932 2 Sheets-Sheet l WHO] [0 o IIHI- THOMS W CARIMMY P HEM/4m 6134/14 L12 7Z5 AGE 2 BY IVE/VT ATTORNEY.

Jan. 30, 1934- T. w. CARRAWAY ET AL 1,945,394

HEAT EXCHANGER Filed July 30. 1952 2 Sheets-Sheet 2 THOMAS W CARR/1W BENMIMIY GRA/MHLIITLEPAGE I N V EN TOR 5.

BY AQIW ATTORNEY Patented Jan. 30, 1934 UNITED STA 'rss PATENT orncs 1,045,394 mul'r axonsxoza Thomas W. Carraway. Providence, 8. 1., and Graham Littlepage, Shreveport, La

Beniaman asaignors to General Fire E or Company, Providence, B. L, a corporation of Dela- Application July30, 1932. 8erial No. 626,408

6 Claim.

monia, for example. The most common medium whose temperature is to be changed by contact with the heat exchanger is air and the device of the invention will hereinafter be described as" though used with such medium, but it is to be understood that the exchanger might be submerged in a liquid, such as water or brine, and effect a similar exchange of heat between its own contained fluid and the liquid medium passing by it.

Heretofore, so far as we are aware, heat exchanger of the unit type, especially those used in refrigerant circuits, have been constructed as an integral unit, usually composed of top and bottom headers with a multiplicity of tubes permanently connecting them. Most of these have proved efficient and generally satisfactory when installed and in operation, but since each such exchanger has been produced as an integral unit at a place of manufacture and shipped in its completely assembled state to the place of installation, the costs of production and transportation have been rather high. And it is obvious that the individual capacity of such an exchanger is definitely limited.

It is among the objects of the present invention to produce a heat exchanger having all the thermal advantages of those heretofore produced but so constructed as to reduce the cost of manufacture and transportation, facilitate commercial handling and installation, and greatly lessen the expense thereof; and withal to provide an exchanger that can be readily adapted to meet any demands reasonably made upon it.

These objects are accomplished by making the exchanger initially in unit sections and then assembling these sections. This-can of course be done at the place of manufacture but it is a particular feature of the invention that the assembling may be done in the fleld or place where the exchanger is to be used. This feature enables the various parts to be more compactly packed for shipment than when the exchanger is completely assembled before being transported. But what is of more importance, the invention provides for the enlargement or reduction of an ex- (Cl. 25'I1 changer, so as to make one of any size or capacity required, simply by adding or removing sections, and changing the fan (and possibly the motor) to meet the-instant demands of the installation.

This makes it unnecessary to make extended surgo veys and inspections before ordering an exchanger, because the salesman can quickly and with sufficient accuracy estimate about the size of exchanger required The unit sections can then be shipped to the place' of installation and u enough of them assembled to satisfy the demands to be made on the exchanger. If later, the demand changes, the exchanger can itself be easily altered to comply most effectively with the new conditions.

At the place of manufacture quantities of unit sections can be made and stored ready for distribution and the wholesaler and jobber can likewise carry such sections in stock ready to be added to already installed units or assembled to fill a new order. But this ties up little money because the sections can be made inexpensively and stored in a minimum of space; and certain elements, such as the fan and motor, need be purchased only after the size and capacity of the exchanger to be installed has been determined.

It is also a feature of the invention that the sections can be cast. This is made practical by the particular form of the sections and especially in the provision of a relatively large passageway of uniform size through each section with a smooth wall surface. This form of passageway permits of the ready removal of a core after casting and enables any foreign particles, such as sand, slugs of metal and the like, to be completely removed. This is important, especially if the exchangers are to be employed in refrigerative systems, where the fluid circulating through the units must also pass through compressors, pumps and automatic valves, for in such systems it essential that no foreign matter be carried along in the flowing fluid. Moreover the ability to cast the unit sections permits metal of high resistance to corrosion to be used, which would not be economically feasible in the form of exchangers now 100 in common use. And even if less expensive metals are used in the castings so that in time these become sufllciently corroded to impede the flow, the provision of the large passageways and the ability to readily take the exchanger apart and 105 In the accompanying drawings is shown the best mode in which we have contemplated applyvided on the top face of the section.

ing the principles of our invention, but this is merely illustrative and it is intended that the patent shall cover by suitable expression in the appended claims whatever features of patentable novelty exist in the invention disclosed.

In the drawings:

Figure .1 is a side elevation of an exchanger, partly in section as'on line 1-1 of Figure 2;

' Figure 2 is an elevation in section as on line 2-2 of Figure 1;

Figure 3 is a perspective of a so-called intermediate section showing the face with tongue around the passageway;

Figure 4 is a plan of the same showing the grooved face thereof;

Figure 5 is a perspective of a section that forms a part of a header; and

Figure 6 is a perspective of an adapter.

Referring more particularly to the drawings, the exchanger comprises a top header 1 and a bottom header 3 each composed of one or more manifold sections 5 and end sections 7, and one or more intermediate sections 9 through which a fluid flows from one header to the other and either gives up heatto or absorbs heat from a medium moving along the surfaces of the sections.

Each intermediate section has a relatively large passageway 11 of uniform size throughout, the wall of which is a smooth surface. This enables a simple core to be used in the casting which can readily be removed. Moreover the dimensions of the passageway permit it to be thoroughly cleaned after the casting or, if necessary, after the section has been in use. A multiplicity of fins 13 are provided on each intermediate section, the peripheral configuration of each fin being preferably rectangular. At the ends of each section these fins are all of the same depth and are connected by a rib 15 extending from the upper to the lower surface of the section. Along the sides of the section the fins are of different depth due to the shape and size of the wall surrounding the passageway 11. This wall, considered vertically, is relatively thin but increases in thickness at the bottom and top of the section as seen clearly in Fig. 2. This increased thickness of wall at the bottom and top of each section is desirable in order that a tongue 17 may be provided on the bottom face of the section around the opening of passageway 11 and a corresponding groove 19 pro- When more than one such section is used, the tongue of one fits into the groove of the next and thus tightness of fit between the sections is insured close by their communicating passageways.

Similar tightness of fit is provided for between the intermediate sections and the manifold sections 5 of the top and bottom headers. These latter sections are provided with an opening or passageway 21 in one wall, conforming in size with the passageway 11 through an intermediate section. Around this opening is a groove 23 adapted to receive the tongue 1'7 of an intermediate section or a tongue 25 of an adapter 2?. The latter is used between a header section and the grooved end of an intermediate section as clearly shown in Figure 2. Each header section is open ended, one end edge having a tongue 29 thereon and the other end a corresponding groove 31, thus permitting one section to be joined to the other in the same manner as the intermediate sections. The end sections 7 of the headers have a groove 33 adapted to receive the tongue of a manifold section or the tongue 35 of another adapter 37. Each end section is provided with a tapped hole 39 by which the pipes conducting the fluid to or from the headers may be connected. If no pipe is attached to any of the end sections a plug 41 may be inserted to close its tapped hole.

In assembling the exchanger, the proper number of sections are placed together, suitable packing compound (not indicated) being placed in the several grooves heretofore mentioned to enhance the tight fit. Tie rods 43 are then extended through suitable sockets 45 provided in the outer walls of the manifold sections 5 and nuts 47 turned on their threaded ends. These secure the,

header sections and intermediate sections firmly together in columnar form. These columns are then in turn secured together by other tie rods 49 which extend through .the header sections and are engaged by nuts 51 seating in suitable sockets 53 in the end sections. Thus the several sections are bound together, with the openings or passageways 21 in the header sections conforming to and in register with the passageways 11 through the intermediate sections.

Suitable plates 55 may then be mounted at the sides between the end sections of the headers to define the passage through which the medium to be heated or cooled is moved. This is accomplished in the illustrated embodiment by a fan 57 driven by a motor 59 mounted in any convenient means on one end of the exchanger. At the other end adjustable deflectors 61 are provided to direct the heat treated medium in any desired direction.

. We claim:

1. A heat exchanger comprising headers having amanifold section and end sections secured together, and an intermediate section between the headers and secured thereto; there being'a passageway in the manifold section conforming to and registering with a passageway in the intermediate section whereby a fluid may flow from one header through said passageways to the other header.

2. A heat exchanger comprising an intermediate section having therethrough an elongated smooth wall passageway of the same size throughout its extent; headers comprising open-ended manifold sections having passageways conforming to and communicating with the passageway of said intermediate section, and end sections for closing said open ends of the manifold sections; means for securing said manifold sections and said intermediate section together so that the passageways will be continuous therethrough; and means for securing said manifold and end sections together.

3. A heat exchanger comprising an intermediate section having an elongated smooth wall passageway of the same size throughout its extent; external fins on said section around said passageway extending laterally from and at right angles to the wall thereof, the fins at the ends of said section being all of substantially the same extent and at the sides thereof being of different extent and varying in width, those nearer the top and bottom of the section being of less width' than the fins more removed from said top and bottom.

4. A heat exchanger composed of a multiplicity of individually cast sections, comprising intermediate sections provided with elongated smooth wall passageways of the same size throughout, and header sections having passageways conforming to and communicating with the pas-v !or securing header sections and any desired number of intermediate sections together so that the passageways thereof will be continuous therethrough; said sections being interchangeable to build up a heat exchanger of any desired size.

5. A heat exchanger comprising a series of intermediate sections, each having an elongated smooth wall passageway 01 the same size throughout; fins on the wall of said passageway, those at the ends of the section being all 01 substantially the same extent and those on the sides or the section varying in extent, increasing from the top and bottom toward the middle or the section; header sections mounted on the top and bottom of the intermediate section having passageways co-extensive with and in communication with the passageway or the intermediate section; and means tor securing said sections together.

8. A heat exchange unit formed of a casting having an elongated passage formed therein provided with smooth parallel walls, said passage being of the same size throughout the entire length thereof, a plurality of fins formed about said passage and extending laterally and at right angles therefrom, the fins extending from the ends of said elongated passage being of substantially the same depth and the fins extending laterally from the sides of said passage increasing in depth from the top and bottom surfaces toward the intermediate portion of the unit, and a connecting rib extending from the upper to the lower surface of the unit on each end thereof adjacent the ends of the elongated passage and formed integral with the end fins of varying depth.

THOMAS W. CARRAWAY. BENJAMAN GRAHAM H'I'ILEPAGE. 

